Clutch mechanisms comprising the following are known from the existing art:                an engine input hub that can be joined to an engine input shaft in particular by means of a torsional damper and/or a flexible plate;        an output hub that can be linked to a transmission, and in particular to a shaft of a gearbox;        a multiple-disc clutch comprising:                    a plurality of first friction elements rotationally integrally connected to the input shaft by means of an input disc carrier and the input hub;            a plurality of second friction elements rotationally integrally connected to the output shaft by means of an output disc carrier and the output hub;                        a control system comprising a housing and an actuator configured to set the clutch in a position located between:                    an engaged position for which the plurality of first friction elements of the clutch are rotationally coupled to the plurality of second friction elements of said clutch; and            a disengaged position for which the plurality of first friction elements of the clutch are rotationally decoupled from the plurality of second friction elements of said clutch.                        
The disadvantage of the known clutch mechanisms is that it is not easy to install them on other elements of the transmission drivetrain, in particular in the housing of a gearbox. More specifically, integrated assembly of such clutch mechanisms often requires specific means for fastening onto the housing of a gearbox, for example. These specific fastening means are generally radially bulky because they must be arranged radially outside the clutch mechanism so as to allow access to said fastening means for the operator performing the installation.
It is therefore necessary to devise specific solutions for each combination of a clutch with an element of the transmission drivetrain, for example a gearbox, so that integration thereof becomes costly and often complex.
An increasing need therefore exists in the automotive field to standardize subassemblies and, as appropriate, to find solutions which are sufficiently versatile to allow existing subassemblies to be installed on one another. More specifically, a need exists to propose economical and standardizable solutions for installing a clutch mechanism on a transmission drivetrain in two steps, the first step comprising installation of the control system on the transmission drivetrain, and the second step comprising installation of the clutch on the control system.
The object of the present invention is to address the above problems at least in large part, and furthermore to produce other advantages.
Another purpose of the invention is to solve at least one of these problems by way of a novel clutch mechanism.
Another purpose of the present invention is to implement, at less cost, installation of a clutch on a transmission drivetrain in two steps.
Another purpose of the present invention is to reduce the mass of a clutch and to standardize the installation thereof on a wide variety of transmission drivetrains.